staging: rtl8723au: rtw_cfg80211_inform_bss(): Use cfg80211_inform_bss()

There is no point in creating a fake beacon frame to call
cfg80211_inform_bss_frame() when we can just call
cfg80211_inform_bss() with the parameters we were sticking into the
fake frame.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>